Received 23 November 2008; accepted 31 August 2009; published online 2 September 2009

Abstract - Although protected for nearly a century, California's sea otters
have been slow to recover, in part due to exposure to fecally-associated protozoal pathogens like
Toxoplasma gondii and Sarcocystis neurona. However, potential impacts from exposure to fecal bacteria have not been systematically explored.
Using selective media, we examined feces from live and dead sea otters from
California for specific enteric
bacterial pathogens (Campylobacter, Salmonella, Clostridium perfringens, C.
difficile and Escherichia coli
O157:H7), and pathogens endemic to the marine environment (Vibrio cholerae,
V. parahaemolyticus and Plesiomonas shigelloides). We evaluated statistical associations between detection of these pathogens in
otter feces and demographic or environmental risk factors for otter
exposure, and found that dead otters
were more likely to test positive for C. perfringens, Campylobacter and V.
parahaemolyticus than were live
otters. Otters from more urbanized coastlines and areas with high freshwater
runoff (near outflows of rivers
or streams) were more likely to test positive for one or more of these
bacterial pathogens. Other risk factors
for bacterial detection in otters included male gender and fecal samples
collected during the rainy season
when surface runoff is maximal. Similar risk factors were reported in prior
studies of pathogen exposure for
California otters and their invertebrate prey, suggesting that land-sea
transfer and/or facilitation of pathogen
survival in degraded coastal marine habitat may be impacting sea otter
recovery. Because otters and humans
share many of the same foods, our findings may also have implications for
human health.